Mounting cups for aerosol tilt valve assemblies of the type shown in FIG. 1 and FIG. 2 are well known. Reference may be made to U.S. Pat. No. 3,954,208 of Brill for a detailed description of the structure and operation of such aerosol tilt valve assemblies, but a brief description will suffice for purposes of describing the present invention.
Referring to FIG. 1, a prior art, or known, tilt valve assembly 10 is seen to include a mounting, or valve, cup 12, a resilient, valve stem mounting grommet 14 and a valve stem 16. All of these elements are symmetrical with respect to a center line axis 18 and are circular in cross sections transverse to the axis 18.
The cup 12 has a tubular, preferably cylindrical, side wall 12A which is joined at one end to a bottom 12B. The opposite end of the side wall 12A defines the open end 12C of the cup 12. A curled peripheral lip 12D surrounding the open end 12C is carried at the opposite end of side wall 12 for mounting connection with a suitable mounting collar 20 at the top 22 of an aerosol container (not shown).
The bottom 12B is generally flat on both the inside and outside of the cup and has a cylindrical collar 12E which surrounds and defines a circular mounting hole 12F.
The grommet 14 is made of resilient rubber-like material and has an elongate neck 14A which extends through mounting hole 12F. A relatively larger body 14B underlies and is normally pressed against the outer surface 12B' of cup bottom 12B. A collar 14C carried by the neck 14A overlies the edge of the peripheral collar to wedge block removal of the grommet neck 14A from mounting hole 12F after full insertion therethrough.
The stem 16 has an elongate tubular body 16A with an outlet 16B from the hollow interior at one end and inlets 16C at the opposite end. The inlets 16C are contained within a chamber 24 defined partially by an enlarged portion 14D' of an axial bore 14D in stem 14. The stem body 16A snugly fits through bore 14D to form a fluid tight seal therebetween.
Likewise, the upper surface 14B' of body 14B is flat and is pressed tight against the flat outer surface 12B' of flat cup bottom 12B to form a seal against passage of fluid therebetween when the stem body 14A is in the non-actuated position, as shown in FIG. 1.
The chamber 24 has an opening which is closed by means of the valve head 16D when the stem 16 is in its non-actuated state, as shown with the stem in an upright position aligned with axis 18.
However, referring to FIG. 2, when the stem 16 is in an actuated, or tilted, position, as shown, the valve head 16D is moved away from sealing engagement with body 14B to open chamber 24 for the entry of fluid 26 from the aerosol container. The fluid 26, being under pressure, is forced from the chamber 24 into inlets 16C and through stem body 16A and out through opening 16B.
Disadvantageously, this tilting action also often creates a small gap 28 between the outside surface 12B' of the cup bottom 12B and upper surface 14B' of grommet body 14B. Repeated tilting can cause increasing amounts of fluid 26 to increase the gap 28 sufficiently to cause leakage of fluid between peripheral collar 12E and collar 14C and onto the exterior of the container and valve cup 12.
A similar leakage problem can occur if the aerosol pressure is sufficient to distort the flat bottom 12B and thereby create a gap 28 between the valve cup 12 and the upper surface 14B' of grommet body 14B. This can result in leakage even when the valve is in its nonactuated position, as shown in FIG. 1. While the pressure can normally be reduced to avoid such undesirable distortion of the valve cup 12, reducing the pressure reduces the amount of fluid 26 which can be stored and retrieved from the aerosol container and thereby disadvantageously decreases the fluid storage capability of the aerosol container.
Other valve assemblies are known which have valve cups with non-flat bodies. These are shown in U.S. Pat. Nos. 2,757,964 of Both et al.; 3,011,686 of Rockwell; 3,074,602 of Shillady et al.; 3,512,685 of Ewald; 3,659,755 of Prussin et al. and 3,866,804 of Stevens. Non-planar container caps or covers, are also known as shown in U.S. Pat. Nos. 2,027,430 of Hansen and 4,467,933 of Wilkinson et al. However, none of these by themselves solve the aforementioned leakage problem of aerosol tilt valve assemblies of the type described above.